1. Field
The present disclosure relates to metal air batteries and gas diffusion layers thereof, and more particularly, to a metal air battery, which may be more easily supplied with air and have an improved energy density.
2. Description of the Related Art
A metal air battery includes a negative electrode capable of ion inclusion/emission and a positive electrode using oxygen in the air as an active material. In the metal air battery, an oxygen reduction/oxidation reaction occurs in the positive electrode and a metal oxidation/reduction reaction occurs in the negative electrode to convert chemical energy into electrical energy. The metal air battery absorbs oxygen in a discharge mode and emits oxygen in a charge mode. Because the metal air battery uses oxygen from the air, the energy density of the battery may be dramatically improved relative to a battery which contains the cathode active material. For example, the metal air battery may have an energy density which is several times than that of a lithium ion battery.
Also, the metal air battery has excellent stability because it has a low possibility of ignition caused by abnormally-high temperatures, and the metal air battery also has a low possibility of causing environmental pollution because it operates by oxygen absorption/emission with reduced use of heavy metals. Nonetheless, there remains a need for an improved metal air battery.